Incidence of atrial fibrillation in patients with renal infarction: A retrospective cohort analysis of the Korean national health insurance registry

BACKGROUND

Regarding the pathophysiology of renal infarction (RI), cardioembolic causes could have large proportion. However, there are notable variations in prevalence of atrial fibrillation (AF) among patients with RI across different studies, ranging from 17 to 65%. The primary objective of this study is to analyze the incidence of AF in patients with RI.

METHODS

This nationwide retrospective cohort study enrolled 5200 patients with RI from the Korean National Institute of Health Services database spanning the years 2013 to 2019. The study accessed the AF incidence rate within 12 months in patients without a prior history of AF. Events occurring within 3 months of RI diagnosis were excluded to mitigate cases diagnosed during the initial screening or those with AF diagnoses that were potentially overlooked in the past.

RESULTS

AF occurred in 19.1% of patients with RI over the entire period (median: 2.5 years, interquartile range 1.04-4.25 years). The majority of AF cases (16.1%) occured within the first year, resulting in an overall incidence rate of 7.0 per 100 person-years. Patients with newly developed AF were, on average, older than those who did not develop AF (64.1 vs. 57.3 years, P < 0.001). The independent predictors of AF were identified as age, male sex, higher body mass index, current smoking, ischemic heart disease, and heart failure.

CONCLUSIONS

Physicians should consider the implementation of active rhythm monitoring for patients with RI to identify potential occurrence of subclinical AF, even if not initially diagnosed during the initial screening after RI diagnosis.

Accuracy of visual estimation of ejection fraction in patients with heart failure using augmented reality glasses

OBJECTIVE

Left ventricular ejection fraction (LVEF) is measured to assess haemodynamic status and cardiac function. It may be difficult to accurately measure in patients with heart failure (HF) as they are often poorly echogenic. The augmented reality (AR) technology is expected to provide real-time guidance that will enable more accurate measurements.

METHODS

A prospective, randomised, case-crossover simulation study was conducted to confirm the effect of AR glasses on echocardiographic interpretation in patients with HF. 22 emergency physicians participated. The participants were randomly assigned to two groups. Group A estimated the visual ejection fraction of echocardiographic video clips without the AR glasses, while group B estimated them with glasses. After a washout period, the two groups crossed over. The estimates were then compared with the ejection fraction measurements obtained by echocardiologists; intraclass correlation coefficient (ICC) was calculated.

RESULTS

The ICC with glasses (0.969, 95% CI 0.966 to 0.971) was higher than without glasses (0.705, 95% CI 0.681 to 0.727) among all participants. In the subgroup analysis, the first-year and second-year residents showed the most significant difference, with an ICC of 0.568 (95% CI 0.508 to 0.621) without glasses compared with 0.963 (95% CI 0.958 to 0.968) with glasses. For the third-year and fourth-year residents group, the ICC was 0.754 (95% CI 0.720 to 0.784) without glasses and 0.972 (95% CI 0.958 to 0.968) with glasses. Among the group of attending physicians, the ICC was 0.807 (95% CI 0.775 to 0.834) without glasses and 0.973 (95% CI 0.969 to 0.977) with glasses.

CONCLUSIONS

AR glasses could be helpful in measuring LVEF and could be more helpful to those with little visual estimation experience.

Home Bioelectrical Impedance Analysis Management System in Patients With Heart Failure: Rationale and Study Design

Body fluid monitoring and management are essential to control dyspnea and prevent re-hospitalization in patients with chronic heart failure (HF). There are several methods to estimate and monitor patient's volume status, such as symptoms, signs, body weight, and implantable devices. However, these methods might be difficult to use for reasons that are slow to reflect body water change, inaccurate in specific patients' condition, or invasive. Bioelectrical impedance analysis (BIA) is a novel method for body water monitoring in patients with HF, and the value in prognosis has been proven in previous studies. We aim to determine the efficacy and safety of home BIA body water monitoring-guided HF treatment in patients with chronic HF. This multi-center, open-label, randomized control trial will enroll patients with HF who are taking loop diuretics. The home BIA group patients will be monitored for body water using a home BIA device and receive messages regarding their edema status and direction of additional diuretics usage or behavioral changes through the linked application system once weekly. The control group patients will receive the usual HF management. The primary endpoint is the change in N-terminal prohormone of brain natriuretic peptide levels from baseline after 12 weeks. This trial will provide crucial evidence for patient management with a novel home BIA body water monitoring system in patients with HF.

Hemo-metabolic impairment in patients with ST-segment elevation myocardial infarction: Data from the INTERSTELLAR registry

BACKGROUND

Not only hemo-dynamic (HD) factors but also hemo-metabolic (HM) risk factors reflecting multi-organ injuries are considered as important prognostic factors in ST-segment elevation myocardial infarction (STEMI). However, studies regarding HM risk factors in STEMI patients are currently limited.

METHOD

Under analysis were 1,524 patients with STEMI who underwent primary percutaneous coronary intervention in the INTERSTELLAR registry. Patients were divided into HM (≥ 2 risk factors) and non-HM impairment groups. The primary outcome was in-hospital all-cause mortality, and the secondary outcome was 1-year all-cause mortality.

RESULTS

Of 1,524 patients, 214 (14.0%) and 1,310 (86.0%) patients were in the HM and non-HM impairment groups, respectively. Patients with HM impairment had a higher incidence of in-hospital mortality than those without (24.3% vs. 2.7%, p < 0.001). After adjusting for confounders, HM impairment was independently associated with in-hospital mortality (inverse probability of treatment weighting [IPTW]-adjusted odds ratio: 1.81, 95% confidence interval: 1.08-3.14). In the third door-to-balloon (DTB) time tertile (≥ 82 min), HM impairment was strongly associated with in-hospital mortality. In the first DTB time tertile ( < 62 min), indicating relatively rapid revascularization, HM impairment was consistently associated with increased in-hospital mortality.

CONCLUSIONS

Hemo-metabolic impairment is significantly associated with increased risk of in-hospital and 1-year mortality in patients with STEMI. It remains a significant prognostic factor, regardless of DTB time.

Clinical efficacy of angiotensin receptor-neprilysin inhibitor in de novo heart failure with reduced ejection fraction

BACKGROUND/AIMS

We aimed to analyze the efficacy of angiotensin receptor-neprilysin inhibitor (ARNI) by the disease course of heart failure (HF).

METHODS

We evaluated 227 patients with HF in a multi-center retrospective cohort that included those with left ventricular ejection fraction (LVEF) ≤ 40% undergoing ARNI treatment. The patients were divided into patients with newly diagnosed HF with ARNI treatment initiated within 6 months of diagnosis (de novo HF group) and those who were diagnosed or admitted for HF exacerbation for more than 6 months prior to initiation of ARNI treatment (prior HF group). The primary outcome was a composite of cardiovascular death and worsening HF, including hospitalization or an emergency visit for HF aggravation within 12 months.

RESULTS

No significant differences in baseline characteristics were reported between the de novo and prior HF groups. The prior HF group was significantly associated with a higher primary outcome (23.9 vs. 9.4%) than the de novo HF group (adjusted hazard ratio 2.52, 95% confidence interval 1.06-5.96, p = 0.036), although on a higher initial dose. The de novo HF group showed better LVEF improvement after 1 year (12.0% vs 7.4%, p = 0.010). Further, the discontinuation rate of diuretics after 1 year was numerically higher in the de novo group than the prior HF group (34.4 vs 18.5%, p = 0.064).

CONCLUSION

The de novo HF group had a lower risk of the primary composite outcome than the prior HF group in patients with reduced ejection fraction who were treated with ARNI.

Temporal Trend of the Incidence and Characteristics of Renal Infarction: Korean Nationwide Population Study

BACKGROUND

Large-scale studies about epidemiologic characteristics of renal infarction (RI) are few. In this study, we aimed to analyze the incidence and prevalence of RI with comorbidities in the South Korean population.

METHODS

We investigated the medical history of the entire South Korean adult population between 2013 and 2019 using the National Health Insurance Service database (n = 51,849,591 in 2019). Diagnosis of RI comorbidities were confirmed with International Classification of Disease, Tenth Revision, Clinical Modification codes. Epidemiologic characteristics, distribution of comorbidities according to etiologic mechanisms, and trend of antithrombotic agents were estimated.

RESULTS

During the 7-years, 10,496 patients were newly diagnosed with RI. The incidence rate increased from 2.68 to 3.06 per 100,000 person-years during the study period. The incidence rate of RI increased with age peaking in the 70s with 1.41 times male predominance. The most common comorbidity was hypertension, followed by dyslipidemia and diabetes mellitus. Regarding etiologic risk factor distribution, high embolic risk group, renovascular disease group, and hypercoagulable state group accounted for 16.6%, 29.1%, and 13.7% on average, respectively. For the antithrombotic treatment of RI, the prescription of antiplatelet agent gradually decreased from 17.0% to 13.0% while that of anticoagulation agent was maintained around 35%. The proportion of non-vitamin K antagonist oral anticoagulants remarkably increased from only 1.4% to 17.6%.

CONCLUSION

Considering the progressively increasing incidence of RI and high prevalence of coexisting risk factors, constant efforts to raise awareness of the disease are necessary. The current epidemiologic investigation of RI would be the stepping-stone to establishing future studies about clinical outcomes and optimal treatment strategies.

Prognostic value of preoperative left ventricular global longitudinal strain for predicting postoperative myocardial injury and mortality in patients undergoing major non-cardiac surgery (SOLOMON study)

BACKGROUND

The usefulness of preoperative measurement of left ventricular global longitudinal strain (LVGLS) for predicting prognosis in patients undergoing non-cardiac surgery has not been evaluated. We analyzed the prognostic value of LVGLS in predicting postoperative 30-day cardiovascular events and myocardial injury after non-cardiac surgery (MINS).

METHODS

This prospective cohort study was conducted in two referral hospitals and included 871 patients who underwent non-cardiac surgery <1 month after preoperative echocardiography. Those with ejection fraction <40%, valvular heart disease, and regional wall motion abnormality were excluded. The co-primary endpoints were the (1) composite incidence of all-cause death, acute coronary syndrome (ACS), and MINS and (2) composite incidence of all-cause death and ACS.

RESULTS

Among the 871 participants enrolled (mean age: 72.9 years; female: 60.8%), there were 43 cases of the primary endpoint (4.9%): 10 deaths, 3 ACS, and 37 MINS. Participants with impaired LVGLS (≤16.6%) had a higher incidence of the co-primary endpoints (log-rank P < 0.001 and 0.015) than those without. The result was similar after adjustment with clinical variables and preoperative troponin T levels (hazard ratio = 1.30, 95% confidence interval [CI] = 1.03-1.65; P = 0.027). In sequential Cox analysis and net reclassification index, LVGLS had an incremental value for predicting the co-primary endpoints after non-cardiac surgery. Among the 538 (61.8%) participants who underwent serial troponin assay, LVGLS predicted MINS independently from the traditional risk factors (odds ratio = 3.54, 95% CI = 1.70-7.36; P = 0.001).

CONCLUSIONS

Preoperative LVGLS has an independent and incremental prognostic value in predicting early postoperative cardiovascular events and MINS.

CLINICAL TRIAL REGISTRATION

URL: https://trialsearch.who.int/. Unique identifiers: KCT0005147.

Clinical, Mutational, and Transcriptomic Characteristics in Elderly Korean Individuals With Clonal Hematopoiesis Driver Mutations

Background

Clonal hematopoiesis of indeterminate potential (CHIP), which is defined as the presence of blood cells originating from somatically mutated hematopoietic stem cells, is common among the elderly and is associated with an increased risk of hematologic malignancies. We investigated the clinical, mutational, and transcriptomic characteristics in elderly Korean individuals with CHIP mutations.

Methods

We investigated CHIP in 90 elderly individuals aged ≥60 years with normal complete blood counts at a tertiary-care hospital in Korea between June 2021 and February 2022. Clinical and laboratory data were prospectively obtained. Targeted next-generation sequencing of 49 myeloid malignancy driver genes and massively parallel RNA sequencing were performed to explore the molecular spectrum and transcriptomic characteristics of CHIP mutations.

Results

We detected 51 mutations in 10 genes in 37 (41%) of the study individuals. CHIP prevalence increased with age. CHIP mutations were observed with high prevalence in DNMT3A (26 individuals) and TET2 (eight individuals) and were also found in various other genes, including KDM6A, SMC3, TP53, BRAF, PPM1D, SRSF2, STAG1, and ZRSR2. Baseline characteristics, including age, confounding diseases, and blood cell parameters, showed no significant differences. Using mRNA sequencing, we characterized the altered gene expression profile, implicating neutrophil degranulation and innate immune system dysregulation.

Conclusions

Somatic CHIP driver mutations are common among the elderly in Korea and are detected in various genes, including DNMT3A and TET2. Our study highlights that chronic dysregulation of innate immune signaling is associated with the pathogenesis of various diseases, including hematologic malignancies.

Prediction of Heart Function and Volume Status in End-Stage Kidney Disease Patients through N-Terminal Pro-Brain Natriuretic Peptide

Background and Objectives: N-terminal pro-brain natriuretic peptide (NT-proBNP) is a biomarker used to predict heart failure and evaluate volume status in hemodialysis (HD) patients. However, it is difficult to determine the cutoff value for NT-proBNP in HD patients. In this study, we analyzed whether NT-proBNP helps predict heart function and volume status in HD patients. Materials and Methods: This prospective observational study enrolled 96 end-stage kidney disease patients with HD. All patients underwent echocardiography and bioimpedance spectroscopy (BIS) after an HD session. Overhydration (OH) was measured by BIS. Laboratory data were obtained preHD, while serum NT-proBNP was measured after HD. Interventions for blood pressure control and dry weight control were performed, and NT-proBNP was re-assessed after a month. Results: There was an inverse correlation between NT-proBNP and ejection fraction (EF) (β = −0.34, p = 0.001). OH (β = 0.331, p = 0.001) and diastolic dysfunction (β = 0.226, p = 0.027) were associated with elevated NT-proBNP. In a subgroup analysis of diastolic dysfunction grade, NT-proBNP increased according to dysfunction grade (normal, 4177 pg/mL [2637–10,391]; grade 1, 9736 pg/mL [5471–21,110]; and grades 2–3, 26,237 pg/mL [16,975–49,465]). NT-proBNP showed a tendency toward a decrease in the ‘reduced dry weight’ group and toward an increase in the ‘increased dry weight’ group compared to the control group (ΔNT-proBNP, −210 pg/mL [−12,899 to 3142], p = 0.104; 1575 pg/mL [−113 to 6439], p = 0.118). Conclusions: We confirmed that NT-proBNP is associated with volume status as well as heart function in HD patients.

Fully automated quantification of cardiac chamber and function assessment in 2-D echocardiography: clinical feasibility of deep learning-based algorithms

We aimed to compare the segmentation performance of the current prominent deep learning (DL) algorithms with ground-truth segmentations and to validate the reproducibility of the manually created 2D echocardiographic four cardiac chamber ground-truth annotation. Recently emerged DL based fully-automated chamber segmentation and function assessment methods have shown great potential for future application in aiding image acquisition, quantification, and suggestion for diagnosis. However, the performance of current DL algorithms have not previously been compared with each other. In addition, the reproducibility of ground-truth annotations which are the basis of these algorithms have not yet been fully validated. We retrospectively enrolled 500 consecutive patients who underwent transthoracic echocardiogram (TTE) from December 2019 to December 2020. Simple U-net, Res-U-net, and Dense-U-net algorithms were compared for the segmentation performances and clinical indices such as left atrial volume (LAV), left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), LV mass, and ejection fraction (EF) were evaluated. The inter- and intra-observer variability analysis was performed by two expert sonographers for a randomly selected echocardiographic view in 100 patients (apical 2-chamber, apical 4-chamber, and parasternal short axis views). The overall performance of all DL methods was excellent [average dice similarity coefficient (DSC) 0.91 to 0.95 and average Intersection over union (IOU) 0.83 to 0.90], with the exception of LV wall area on PSAX view (average DSC of 0.83, IOU 0.72). In addition, there were no significant difference in clinical indices between ground truth and automated DL measurements. For inter- and intra-observer variability analysis, the overall intra observer reproducibility was excellent: LAV (ICC = 0.995), LVEDV (ICC = 0.996), LVESV (ICC = 0.997), LV mass (ICC = 0.991) and EF (ICC = 0.984). The inter-observer reproducibility was slightly lower as compared to intraobserver agreement: LAV (ICC = 0.976), LVEDV (ICC = 0.982), LVESV (ICC = 0.970), LV mass (ICC = 0.971), and EF (ICC = 0.899). The three current prominent DL-based fully automated methods are able to reliably perform four-chamber segmentation and quantification of clinical indices. Furthermore, we were able to validate the four cardiac chamber ground-truth annotation and demonstrate an overall excellent reproducibility, but still with some degree of inter-observer variability.

Association between inter-leg blood pressure difference and cardiovascular outcome in patients undergoing percutaneous coronary intervention

Background

Although the inter-arm blood pressure (BP) difference has been advocated to be associated with cardiovascular events, the implication of inter-leg BP difference has not been well established. This study was conducted to investigate whether inter-arm and -leg BP differences have prognostic value in patients undergoing percutaneous coronary intervention (PCI).

Methods

In this prospective study, we consecutively enrolled 667 patients who underwent PCI. Both arm and leg BPs were measured at the day after PCI. The primary outcome was a major adverse cardiovascular event (MACE) including cardiac death, acute coronary syndrome, coronary revascularization, stroke, and hospitalization for heart failure during the follow-up period.

Results

Mean age was 64.0±11.1 years old, and males were predominant (70.5%). During a mean follow-up period of 3.0 years, MACE occurred in 209 (31.3%) patients. The inter-leg systolic BP difference (ILSBPD) was significantly higher in patients with MACE than those without (9.9±12.3 vs. 7.2±7.5 mmHg, P = 0.004). The inter-arm systolic BP difference was not significantly different between patients with and without MACE (P = 0.403). In multivariable Cox regression analysis, increased ILSBPD was independently associated with the development of MACE (per 5 mmHg; hazard ratio, 1.07; 95% confidence interval, 1.01–1.14). The inter-arm systolic BP difference was not associated with MACE in the multivariable analysis.

Conclusion

Increased ILSBPD was independently associated with worse cardiovascular outcomes after PCI. As ILSBPD is easy to measure, it may be helpful in the risk stratification of patients undergoing PCI.

Association Between Change in Metabolic Syndrome Status and Risk of Incident Atrial Fibrillation: A Nationwide Population-Based Study

Backgroud There is a paucity of information on whether changes in metabolic syndrome (MetS) status affect the risk of new-onset atrial fibrillation (AF). We aimed to evaluate whether changes in MetS status and components of MetS affect AF risk using data from a nationwide observational cohort. Methods and Results A total of 7 565 531 adults without prevalent AF (mean age, 47±14 years) who underwent 2 serial health examinations by the Korean National Health Insurance Cooperation were identified. The patients were categorized into 4 groups according to the change in MetS status in serial evaluations, as follows: patients with persistent MetS (n=1 388 850), healthy patients newly diagnosed with MetS in the second evaluation (n=608 158), patients with MetS who were healthy in the second evaluation (n=798 555), and persistently healthy individuals (n=4 769 968). During a mean 7.9-year follow-up, incident AF was diagnosed in 139 305 (1.8%) patients. After multivariable adjustment, the AF risk was higher by 31% in the patients with persistent MetS , 26% in the patients with MetS who were healthy in the second evaluation, and 16% in the healthy patients newly diagnosed with MetS in the second evaluation compared with the persistently healthy individuals. Regardless of the MetS component type, the AF risk correlated with changes in the number of components. The risk of AF was strongly correlated with MetS status changes in the young and middle-age groups (20-39 years and 40-64 years, respectively) than in the elderly group (≥65 years). Conclusions Dynamic changes in MetS status and persistent MetS were associated with an increased risk of AF in a large-scale Asian population.

Increased atrial fibrillation risk in Parkinson's disease: A nationwide population-based study

OBJECTIVE

Parkinson's disease (PD) is the second most common neurodegenerative disorder associated with various morbidities. Although the relationship between cardiovascular disease and PD has been studied, a paucity of information on PD and atrial fibrillation (AF) association exists. Thus, we aimed to investigate whether patients with PD have an increased risk of AF.

METHODS

This study included 57,585 patients with newly diagnosed PD (≥40-year-old, mean age 69.7 years, men 40.2%) and without a history of AF from the Korean National Health Insurance Service (NHIS) database between 2010 and 2015. Furthermore, an equal number of age- and sex-matched subjects without PD were selected for comparison. The primary outcome was new-onset AF.

RESULTS

During the mean follow-up period of 3.4 ± 1.8 years, AF was newly diagnosed in 3,665 patients. A significantly higher incidence rate of AF was noted among patients with PD than among patients without PD (10.75 and 7.86 per 1000 person-year, respectively). Multivariate Cox-regression analysis revealed that PD was an independent risk factor for AF (hazard ratio [HR]: 1.27, 95% confidence interval [CI]: 1.18-1.36). Furthermore, subgroup analyses revealed that AF risk was higher in the younger age subgroups, and compared with the non-PD group, the youngest PD group (age: 40-49 years) had a threefold increased risk of AF (HR: 3.06, 95% CI: 1.20-7.77).

INTERPRETATION

Patients with PD, especially the younger age subgroups, have an increased risk of AF. Active surveillance and management of AF should be considered to prevent further complications.

Clinical impact of atrial fibrillation in a nationwide cohort of hypertrophic cardiomyopathy patients

Background

The clinical implications of atrial fibrillation (AF) in hypertrophic cardiomyopathy (HCM) patients are incompletely characterized. We investigated the impact of AF on stroke and mortality, assessed the performance of the CHA2DS2-VASc score, and explored the predictors of stroke in HCM patients.

Methods

A nationwide cohort of HCM patients (n=8,349, mean age 60.7) identified from 2010 to 2015 from the Korean National Health Insurance database were followed up for occurrence of ischemic stroke or all-cause death.

Results

During a mean follow-up of 2.5 years, the incidence rate of stroke was 2.69 and 5.87, and mortality rate was 2.06 and 4.44 per 100 person-years in non-AF and AF patients, respectively. AF was independently associated with a 60% and 50% increased risk for stroke and all-cause mortality, respectively. The AF-associated increase in risk of stroke was more prominent in HCM patients with no or few risk factors. The CHA2DS2-VASc score showed poor discrimination of stroke risk in HCM patients with AF, mostly due to the high incidence of stroke in patients with scores of 0 or 1. Traditional risk factors were not always associated with stroke in HCM patients with AF; age, heart failure, high blood pressure and GGT were the strongest predictors of stroke in this population. HCM patients without AF also showed increased incidence of stroke at CHA2DS2-VASc ≥1.

Conclusions

AF was independently associated with increased risks for stroke and all-cause mortality in patients with HCM. The CHA2DS2-VASc score showed poor discrimination of stroke risk in HCM patients with AF.

Early Surgery versus Watchful Waiting in Patients with Moderate Aortic Stenosis and Left Ventricular Systolic Dysfunction

Background and Objectives

Severe aortic stenosis (AS) with left ventricular systolic dysfunction (LVSD) is a class I indication for aortic valve replacement (AVR) but this recommendation is not well established in those at the stage of moderate AS. We investigate the clinical impact of AVR among patients with moderate AS and LVSD.

Methods

From 2001 to 2017, we consecutively identified patients with moderate AS and LVSD, defined as aortic valve area 1.0–1.5 cm² and left ventricular ejection fraction <50%. The primary outcome was all-cause death. The outcomes were compared between those who underwent early surgical AVR (within 2 years of index echocardiography) at the stage of moderate AS versus those who were followed medically without AVR at the outpatient clinic.

Results

Among 255 patients (70.1±11.3 years, male 62%), 37 patients received early AVR. The early AVR group was younger than the medical observation group (63.1±7.9 vs. 71.3±11.4) with a lower prevalence of hypertension and chronic kidney disease. During a median 1.8-year follow up, 121 patients (47.5%) died, and the early AVR group showed a significantly lower all-cause death rate than the medical observation group (5.03PY vs. 18.80PY, p<0.001). After multivariable Cox-proportional hazard regression adjusting for age, sex, comorbidities, and laboratory data, early AVR at the stage of moderate AS significantly reduced the risk of death (hazard ratio, 0.43; 95% confidence interval 0.20–0.91; p=0.028).

Conclusions

In patients with moderate AS and LVSD, AVR reduces the risk of all-cause death. A prospective randomized trial is warranted to confirm our findings.

Trends of the prevalence and incidence of hypertrophic cardiomyopathy in Korea: A nationwide population-based cohort study

Temporal trends of the prevalence and incidence of hypertrophic cardiomyopathy (HCM) have not been well established in Asian populations. Using the Korean National Health Insurance Services database, we identified patients with a confirmed diagnosis of HCM between 2010 and 2016. The annual prevalence and incidence of HCM, and their clinical characteristics were investigated. The prevalence of HCM has increased from 0.016% (n = 6313) in 2010 to 0.031% (n = 13,035) in 2016. During a 7-year period, 13,229 patients were newly diagnosed with HCM. The incidence rate increased from 4.15 (per 100,000 person-years) in 2010 to 5.6 in 2016. The prevalence and incidence of HCM increased with age and peaked during the 70s, with male predominance in all age groups. Chest pain is the most frequent clinical presentation followed by shortness of breath and syncope. Hypertension and dyslipidemia were the two most common comorbidities. Heart failure and atrial fibrillation was diagnosed in about 1/3 and 1/4 of patients with HCM, respectively. The prevalence and incidence of HCM gradually increased from 2010 to 2016, possibly due to heightened recognition of the disease. Given the progressively high incidence of HCM with age and high prevalence of coexisting modifiable risk factors, continued efforts are required to increase awareness regarding HCM-related symptoms and potential complications.

P1274 Early surgery versus watchful waiting in patients with moderate aortic stenosis and left ventricular systolic dysfunction

Background

Aortic stenosis (AS) induces significant pressure overload to the left ventricle (LV) and its burden may increase if there is concomitant LV systolic dysfunction. Severe AS with LV systolic dysfunction is a class I indication for aortic valve replacement (AVR) irrespective of symptoms, however, this recommendation is not well established in those with moderate AS and LV systolic dysfunction. In this study, we sought to investigate the clinical impact of surgical AVR among patients with moderate AS and LV systolic dysfunction.

Methods

From 2001 to 2017, we retrospectively but consecutively identified patients with moderate AS and LV systolic dysfunction from a single tertiary hospital. Moderate AS was defined as aortic valve area between 1.0 and 1.5cm2 and LV systolic dysfunction as LV ejection fraction less than 50%. The primary outcome was all-cause death and we additionally analyzed cardiac death as a secondary endpoint. The outcomes were compared between those who underwent early surgical AVR at the stage of moderate AS versus those who were followed without AVR at the outpatient clinic.

Results

Among a total of 257 patients with moderate AS and concomitant LV systolic dysfunction (70.0 ± 11.3 years, 63.4% of male), 34 patients received early AVR. Patients in the AVR group was younger than the observation group (64.2 ± 8.1 vs. 70.9 ± 11.5, respectively), and had a lower prevalence of hypertension and chronic kidney disease. During a mean of 3-year follow up, 112 patients (47.5%) died and the overall death rate was 15.367 per 100 person-year (PY). The AVR group showed a significantly lower rate of all-cause death than the observation group (5.241PY vs. 18.160PY, p-value = 0.002). After multivariable Cox proportional hazard regression adjusting for age, sex, comorbidities and laboratory data, early AVR at the stage of moderate AS significantly reduced the risk of all-cause death (hazard ratio [HR] 0.340, 95% confidence interval [CI] 0.117 - 0.985, p-value = 0.047). However, there was no risk reduction of cardiac death (HR 0.578 95% CI 0.150 - 2.231, p-value = 0.426).

Conclusions

In patients with moderate AS and LV systolic dysfunction, AVR reduces the risk of all-cause death. A prospective design study is warranted to confirm our findings in the near future.

Abstract P1274 Figure. Kaplan-Meier curves for deaths

P785 Left ventricular geometry and myocardial contractility modulate impact of statins on prognosis in patients with acute heart failure

Funding Acknowledgements

N/A

Background/Introduction: The benefit of statins in patients with heart failure (HF) remains controversial and the mechanism of action is largely speculative. We investigated whether survival benefit with statins differs according to left ventricular (LV) geometry and myocardial contractility in acute HF patients.

Methods

We enrolled 1792 acute HF patients receiving statins and 2296 patients not receiving statins admitted from 2009 to 2016. The LV and right ventricular (RV) global longitudinal strain (GLS) was assessed as a measure of myocardial contractility. Patients were classified into 2 groups based on ischemic etiology of HF and further divided into 4 subgroups according to the median values of LV-GLS or RV-GLS. The primary outcome was 5-year all-cause mortality. The study protocol was approved by the ethics committee at each institute and complied with the Declaration of Helsinki. The need for written informed consent was waived.

Results

During the 5-year follow-up, 1740 (40.4%) patients died and they had more unfavorable baseline characteristics. Statin therapy was significantly associated with improved survival in overall patients and in both groups with and without ischemic etiology (all p &lt;0.001). Patients with concentric remodeling/hypertrophy and eccentric hypertrophy demonstrated survival benefit with statin therapy (P = 0.033, 0.004, and 0.008, respectively), while those with normal geometry did not (p = 0.123). In the non-ischemic HF group, survival benefit with statin therapy was confined to patients with low LV-GLS (p = 0.045) or those with low RV-GLS p = 0.003). On the contrary, in ischemic HF group, survival benefit with statin therapy was observed in all patients regardless of the values of LV-GLS or RV-GLS. Significant interactions were present between statin use and diabetes mellitus and IHD (p for interaction = 0.027 and 0.003, respectively) regarding mortality.

Conclusions

LV geometry and myocardial contractility may modulate the effects of statins in patients with acute HF. These echocardiographic measures can provide prognostic information to guide tailored statin treatment in this population. Our findings may also help to develop more well-designed prospective studies, in terms of a more homogenous study population, to confirm survival benefit with statin therapy.

Abstract P785 Figure. Multivariate Cox survival curves

Risk of Atrial Fibrillation in Relation to the Time Course of Type 2 Diabetes Mellitus and Fasting Blood Glucose

The relation of progression of type 2 diabetes and detailed fasting glucose level with risk of atrial fibrillation (AF) is not well known. A total of 6,199,629 subjects not diagnosed with AF who underwent health check-up in 2009 were included from the Korean National Health Insurance Service database. Risk of AF was compared among subjects with normal fasting glucose (NFG), subjects with impaired fasting glucose (IFG), patients with diabetes duration <5 years (early diabetes mellitus [DM]), and patients with diabetes duration ≥5 years (late DM). Next, risk of AF stratified by fasting glucose level per 10 mg/dL was assessed. During a mean follow-up of 7.2 years, the risk of AF significantly increased across the time course of type 2 diabetes (adjusted hazard ratio (aHR) 1.04, 95% confidence interval (CI) 1.02 to 1.05 for IFG; aHR 1.06, 95% CI 1.04 to 1.08 for early DM; aHR 1.09, 95% CI 1.07 to 1.11 for late DM). The risk of AF was significantly higher in subjects who progressed to type 2 diabetes in the IFG group. Risk of AF increased with a 10 mg/dL increment of fasting blood glucose (p-for-trend <0.0001). However, there was a U-shape relationship between fasting blood glucose and risk of AF in those who received antidiabetic medication. In conclusion, the risk of AF increased with the time course of type 2 diabetes. However, low blood glucose in antidiabetic medication user was associated with an increased risk of AF.

Fluctuating renal function and the risk of incident atrial fibrillation: a nationwide population-based study

Although chronic kidney disease is known to increase the risk of atrial fibrillation (AF), the impact of the variability of renal function on the risk of incident AF is unknown. We aimed to evaluate the association between variability of renal function and the risk of developing AF among the general population. We evaluated a total of 3,551,249 adults who had three annual health check-ups provided by the National Health Insurance Service. The variability of renal function was defined as GFR-VIM, which is variability independent of the mean (VIM) of creatinine-based estimated glomerular filtration rate (eGFR). The study population was divided into four groups (Q1-4) based on the quartiles of GFR-VIM, and the risks of incident AF by each group were compared. During a mean of 3.2 ± 0.5 years follow-up, incident AF occurred in 15,008 (0.42%) subjects. The incidence rates of AF increased from Q1 to Q4 (0.98, 1.42, 1.27, and 1.63 per 1,000 person-years, respectively). Adjusting with multiple variables, Q4 showed an increased risk of incident AF compared to Q1 (hazard ratio (HR) 1.125, 95% confidence interval (CI) 1.071-1.181). Variability of serum creatinine or other definitions of variability showed consistent results. On subgroup analyses, Q4 in males or those with a decreasing trend of eGFR had significantly increased risks of incident AF compared to Q1 (HR 1.127, 95% CI 1.082-1.175; and HR 1.115, 95% CI 1.059-1.173, respectively). High variability of eGFR was associated with an increased risk of incident AF, particularly in males or those with decreasing trends of eGFR during follow-up.

Extensive left atrial ablation was associated with exacerbation of left atrial stiffness and dyspnea

INTRODUCTION

The left atrium (LA), including the pulmonary vein antrum, is the main target of catheter ablation for atrial fibrillation (AF). However, there is a lack of data on the effect of extensive LA ablation on LA stiffness. This study sought to investigate the impact of extensive LA ablation on LA stiffness and dyspnea after the restoration of sinus rhythm.

METHODS

In total, 97 patients with AF (80 patients who only underwent pulmonary vein isolation [PVI] and 17 patients who underwent extensive LA ablation) were investigated. Extensive LA ablation was defined as PVI plus at least two sets of LA linear-line ablation. LA stiffness was estimated using the ratio of E/e' to global longitudinal LA strain, as measured by echocardiography. The clinical outcomes we evaluated were AF recurrence and composite dyspnea, which we defined as newly prescribed diuretics or hospitalization for heart failure.

RESULTS

Patients were 59.3 ± 10.0 years old on average, and 68 (70.1%) were male. There were no significant differences in baseline characteristics or echocardiographic parameters before ablation between the two groups. After ablation, LA stiffness was higher in the extensive ablation group compared with that in the PVI group (0.9 ± 0.6 vs 0.5 ± 0.3, respectively, P = .017). Multivariable linear regression analysis showed that extensive ablation increased LA stiffness (ß = 0.363, P < .001). AF recurrence was similar in both groups; however, composite dyspnea outcomes were worse in the extensive ablation group (P = .003).

CONCLUSION

Extensive LA ablation was associated with a worsening of LA stiffness. This might explain dyspnea despite the successful restoration of sinus rhythm.

Bodyweight fluctuation is associated with increased risk of incident atrial fibrillation

BACKGROUND

Obesity and weight gain are established risk factors for atrial fibrillation (AF).

OBJECTIVE

The purpose of this study was to investigate whether bodyweight variability is also a risk factor for AF development.

METHODS

A nationwide population-based cohort of 8,091,401 adults from the Korean National Health Insurance Service database without a history of AF and with ≥3 measurements of bodyweight over a 5-year period were followed up for incident AF. Intraindividual bodyweight variability was calculated using variability independent of mean, and high bodyweight variability was defined as the quartile with the highest variability (Q4) with Q1-Q3 as reference.

RESULTS

During median 8.1 years of follow-up, each increase of 1 SD in bodyweight variability was associated with a 5% increased risk of AF development, and the quartile with the highest bodyweight variability showed 14% increased risk of AF development compared to the quartile with the lowest variability (hazard ratio 1.14; 95% confidence interval 1.12-1.15), after adjustment for baseline bodyweight, height, age, sex, lifestyle factors, and comorbidities. High bodyweight variability was significantly associated with AF development in all baseline body mass index (BMI) groups except the very obese (BMI ≥30), and this association was stronger in subjects with lower bodyweight. High bodyweight variability was associated with increased risk of incident AF in all weight change groups, with a stronger association in those who lost weight.

CONCLUSION

Bodyweight fluctuation was independently associated with an increased risk of AF development, especially in individuals with low bodyweight, and regardless of weight gain or loss.

Validation of the hypertrophic cardiomyopathy risk-sudden cardiac death calculator in Asians

Objective

The hypertrophic cardiomyopathy (HCM) risk-sudden cardiac death (SCD) calculator endorsed by the 2014 European Society of Cardiology has not been independently validated in the Asians. We aimed to investigate whether the HCM Risk-SCD calculator effectively predicts SCD in Korean HCM population.

Methods

An observational, longitudinal cohort study was performed in 730 patients with HCM from 2007 to 2017. The primary endpoint was a composite of SCD and appropriate implantable cardioverter-defibrillator (ICD) therapy.

Results

During a follow-up period of 4288 person-years, 16 (2.2%) patients reached the primary endpoint. This validation study revealed a calibration slope of 0.892 and C-statistics of 0.718. The primary endpoint occurred in 1.1% (7/615), 4.6% (3/65) and 12.0% (6/50) of low-risk, intermediate-risk and high-risk groups, respectively. Although most patients (85.2%) without the primary endpoint were classified into the low-risk group, 7 of 11 SCD (63.6%) occurred in the low-risk group. In univariable and multivariable analysis, sex (woman) was significantly associated with the primary endpoint and emerged as independent predictor. The addition of sex to the HCM Risk-SCD calculator significantly improved the predictive value of the primary endpoint (net reclassification improvement 0.557, p=0.015).

Conclusions

In the Korean HCM population, the HCM Risk-SCD calculator had a high negative predictive value and accuracy for predicting SCD or appropriate ICD therapy, but misclassified a few patients experiencing the primary endpoint as low-risk or intermediate-risk groups.

Association of arterial stiffness with aortic calcification and tortuosity

Impact of arterial stiffness on aortic morphology has not been well evaluated. We sought to investigate the association of brachial-ankle pulse wave velocity (baPWV) with aortic calcification and tortuosity.A total of 181 patients (65.4 ± 10.4 years, males 59.7%) who underwent computed tomographic angiography and baPWV measurement within 1 month of study entry were retrospectively reviewed. Aortic calcification was quantified by the calcium scoring software system. Aortic tortuosity was defined as the length of the midline in the aorta divided by the length of linear line from the aortic root to the distal end of the thoraco-abdominal aorta. In simple correlation analyses, baPWV was correlated with aortic calcification (r = 0.36, P < .001) and tortuosity (r = 0.16, P = .030). However, these significances disappeared after controlling for confounders in multivariate analyses. Factors showing an independent association with aortic calcification were age (β = 0.37, P < .001), hypertension (β = 0.19, P = .003), diabetes mellitus (β = 0.12, P = .045), smoking (β = 0.17, P = .016), and estimated glomerular filtration rate (β = -0.25, P = .002). Factors showing an independent association with aortic tortuosity were age (β = 0.34, P < .001), body mass index (β = -0.19, P = .018), and diabetes mellitus (β = -0.21, P = .003).In conclusion, baPWV reflecting arterial stiffness was not associated with aortic calcification and tortuosity. Traditional cardiovascular risk factors were more influential to aortic geometry. Further studies with a larger sample size are needed to confirm our results.

Visit-to-visit variability of metabolic parameters and risk of heart failure: A nationwide population-based study

BACKGROUND

This study examined the effects of variability of four metabolic parameters, namely systolic blood pressure (BP), body mass index (BMI), fasting blood glucose (FBG), and total cholesterol level (TC) on the risk of HF. The effects of metabolic parameter variability on the risk of heart failure (HF) remain unclear.

METHODS

We studied individuals aged ≥40 years who had undergone ≥3 health check-ups under the Korean National Health Insurance Corporation during 2009 and 2012, and those who did not have hypertension, diabetes, or dyslipidemia. BP, BMI, FBG, and TC were measured at every visit. We defined the variability of each parameter using the variability independent of the mean (VIM) method. VIMs were categorized into four groups according to quartiles. The metabolic variability (MV) score for each subject was defined as the number of VIMs in the highest quartile.

RESULTS

Among the 3,820,191 subjects, 17,253 (0.45%) had incident HF during a mean 5.3 ± 1.1 years of follow-up. High variability of each parameter was associated with increased HF risk, which increased according to the MV score. After multivariable adjustment, compared to subjects with MV score = 0, subjects with MV score = 1-4 had an increased risk of HF (adjusted HR [95% CI], 1.15 [1.10-1.19] for MV score = 1, 1.33 [1.28-1.39] for MV score = 2, 1.48 [1.40-1.57] for MV score = 3, 1.74 [1.55-1.96] for MV score = 4 [p-for-trend ≪0.0001]).

CONCLUSIONS

High variability of BP, BMI, FBG, and TC was synergistically associated with a higher incidence of new-onset HF.

Increased risk of atrial fibrillation in patients with inflammatory bowel disease: A nationwide population-based study

BACKGROUND

Inflammatory bowel disease (IBD), a chronic inflammatory disease of the gastrointestinal tract, could play a role in the pathophysiology of atrial fibrillation (AF).

AIM

To investigate the association between IBD and AF development.

METHODS

We performed a population-based cohort study using records in the Korean National Health Insurance Services database between 2010 and 2014. A total of 37696 patients with IBD (12349 with Crohn’s disease and 25397 with ulcerative colitis) were identified. The incidence rate of newly diagnosed AF in patients with IBD was compared with that in a 3 times larger cohort of 113088 age- and sex-matched controls without IBD.

RESULTS

During 4.9 ± 1.3 years of follow-up, 1120 patients newly diagnosed with AF (348 in the IBD group and 772 in controls) were identified. After adjustments using multivariable Cox proportional hazards, patients with IBD were at a 36% [95% confidence interval (CI) 20%-54%] higher risk of AF than controls. The association between IBD and the development of AF was stronger in younger than in older patients. Patients without cardiovascular risk factors showed a higher risk of AF primarily. Additionally, patients receiving immun-omodulators [Hazard ration (HR) 1.46, 95%CI 1.31-1.89], systemic corticosteroids (HR 1.37, 95%CI 1.10-1.71), or biologics agents (HR 2.38, 95%CI 1.51-3.75) were at higher risk of AF than patients without them.

CONCLUSION

IBD significantly increased the risk of AF, and the impact of IBD on developing AF was in patients with moderate to severe disease.

Ankylosing spondylitis: A novel risk factor for atrial fibrillation - A nationwide population-based study

BACKGROUND

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease, associated with a number of cardiovascular diseases. We sought to investigate whether AS increases the risk of atrial fibrillation (AF) in a nationwide population-based study.

METHODS

A total of 14,129 patients newly diagnosed with AS (mean age 41.8 ± 15.3 years, 72% male) were recruited from the Korean National Health Insurance Service database between 2010 and 2014 and followed up for new onset AF. Age- and sex-matched non-AS subjects (1:5, n = 70,645) were selected and compared with the AS patients.

RESULTS

During a mean follow-up of 3.5 years, AF was newly diagnosed in 486 patients (114 patients of the AS group). The AS patients developed AF more frequently than the non-AS subjects (2.32 vs. 1.51 per 1000 person-years). In multivariate Cox regression analysis, AS was an independent risk factor for AF (Hazard ratio [HR] 1.28, 95% confidence interval [1.03-1.58]). The AS with tumor necrosis factor inhibitor (TNFi) therapy group showed higher risk for AF (HR 1.60 [1.02-2.39]). In younger patients of the AS group (patients <40 years old), the risk for AF was three times higher than patients at same age in the non-AS group. AS was an independent risk factor for AF in men, but not in women (HR 1.53 [1.18-1.95]; HR 1.42 [0.94-2.08], respectively).

CONCLUSIONS

AS was an independent risk factor for AF, especially in those under 40 years of age and those administered TNFi. It would be reasonable to screen for AF and stroke prevention in these high-risk patients.

Prognostic efficacy of platelet count in patients with nonvalvular atrial fibrillation

BACKGROUND

The prognostic efficacy of quantitative platelet activity in atrial fibrillation (AF) remains unclear.

OBJECTIVE

The purpose of this study was to evaluate the platelet count (PLT) as a prognostic indicator in patients with nonvalvular AF.

METHODS

Data on 10,978 patients with nonvalvular AF were retrieved from a prospective registry of a single medical center in Korea. Cumulative risk for stroke and bleeding events were compared between patients with normal PLT (n = 8322), mild thrombocytopenia (n = 1791), and moderate to severe thrombocytopenia (n = 865) after propensity score matching. Prediction models for stroke were derived by conventional risk factors (model 1) and by combining PLT with model 1 (model 2), and model performance was assessed by area under the receiver operator characteristics curve (AUC).

RESULTS

During the follow-up period, 7.3%, 7.0%, and 4.5% had stroke and 7.6%, 10.8%, and 17.2% had bleeding events in the normal PLT, mild, and moderate to severe thrombocytopenia groups, respectively. Compared to the normal PLT group, the moderate to severe thrombocytopenia group showed a lower risk of stroke (hazard ratio [HR] 0.57; 95% confidence interval [CI] 0.40-0.80; P = .002). A reverse relationship was found between PLT and bleeding risk (moderate to severe thrombocytopenia: HR 2.19; 95% CI 1.77-2.70; P <.001; mild thrombocytopenia: HR 1.43; 95% CI 1.18-1.73; P <.001). Compared to model 1, model 2 showed significant improvement in risk prediction (AUC 0.628 vs 0.644; P <.001).

CONCLUSION

A lower PLT was associated with a lower risk of stroke and a higher risk of bleeding events. PLT combined with conventional risk factors showed significant improvement in prediction for stroke.

Pharmacogenetics of the mycophenolic acid targets inosine monophosphate dehydrogenases IMPDH1 and IMPDH2: gene sequence variation and functional genomics

BACKGROUND AND PURPOSE

Inosine monophosphate dehydrogenases, encoded by IMPDH1 and IMPDH2, are targets for the important immunosuppressive drug, mycophenolic acid (MPA). Variation in MPA response may result, in part, from genetic variation in IMPDH1 and IMPDH2.

EXPERIMENTAL APPROACH

We resequenced IMPDH1 and IMPDH2 using DNA from 288 individuals from three ethnic groups and performed functional genomic studies of the sequence variants observed.

KEY RESULTS

We identified 73 single nucleotide polymorphisms (SNPs) in IMPDH1, 59 novel, and 25 SNPs, 24 novel, in IMPDH2. One novel IMPDH1 allozyme (Leu275) had 10.2% of the wild-type activity as a result of accelerated protein degradation. Decreased activity of the previously reported IMPDH2 Phe263 allozyme was primarily due to decreased protein quantity, also with accelerated degradation. These observations with regard to the functional implications of variant allozymes were supported by the IMPDH1 and IMPDH2 X-ray crystal structures. A novel IMPDH2 intron 1 SNP, G > C IVS1(93), was associated with decreased mRNA quantity, possibly because of altered transcription.

CONCLUSIONS AND IMPLICATIONS

These results provide insight into the nature and extent of sequence variation in the IMPDH1 and IMPDH2 genes. They also describe the influence of gene sequence variation that alters the encoded amino acids on IMPDH function and provide a foundation for future translational studies designed to correlate sequence variation in these genes with outcomes in patients treated with MPA.

Non-association of estrogen receptor genotypes with bone mineral density and bone turnover in Korean pre-, peri-, and postmenopausal women

Estrogen is known to play a critical role in both skeletal maturity and the rate of bone loss. This suggests the possibility that the estrogen receptor (ER) gene is one of the candidate genes that determines peak bone density and/or bone turnover rate. We investigated two established restriction fragment length polymorphisms (RFLPs) in intron 1 at the ER gene, represented as PvuII and XbaI. In 598 healthy Korean women aged 20-74 years, we examined the association of these ER genotypes with bone mineral density (BMD) and bone turnover status. The distribution of the PvuII and XbaI RFLPs was as follows: pp 205 (34.3%), Pp 308 (51.5%), PP 85 (14.2%) and xx 384 (64.2%), Xx 180 (30.1%), XX 34 (5.7%), respectively (where capital letters signify the absence of, and lower-case letters signify the presence of, the restriction site of each RFLP). No significant genotypic differences were found in BMD and bone markers. We grouped the subjects into three categories according to their menstrual status: 104 premenopausal women with regular menstruation, 182 perimenopausal women who had amenorrhea of not less than 3 months and not more than 12 months' duration, and 312 postmenopausal women whose last menstruation was at least 12 months previously. No significant genotypic difference in either BMD or bone markers was found in any of these three groups. Furthermore we categorized women in peri- and postmenopause into a high loser group and a normal loser group according to the level of bone resorption markers. There was no difference in genotypic proportions between the high and normal loser groups. Our data suggest that these ER polymorphisms are not associated with BMD or bone turnover in Korean women.

Assessment of UK practice for management of acute childhood idiopathic thrombocytopenic purpura against published guidelines

BACKGROUND

Guidelines for management of acute immune thrombocytopenic purpura (ITP) in childhood were published in 1992. Regional audit in 1995 showed substantial variation in clinical practice not related to clinical differences in patient groups, which indicated a need for national audit.

METHODS

Individuals aged from birth to their 16th birthday newly presenting with ITP were identified over 14 months by regular mailing of paediatricians and haematologists for case notification. Information was obtained from follow-up by a detailed questionnaire.

FINDINGS

ITP was clinically mild and benign in 323 (76%) of 427 cases, including 181 (70%) of 260 cases with platelet counts below 10 x 10(9)/L. There were no deaths or intracranial haemorrhages. There was a substantial discrepancy between clinical practice and published guidelines: many children were admitted to hospital and received treatment unnecessarily; there was overuse of intravenous immunoglobulin (IVIg) as first-line therapy (94 children); children received steroids without marrow examination; and there was inappropriate use of platelet transfusions (41 with mild or moderate disease).

INTERPRETATION

Our results indicate a need for change in practice.